1. Field of the Invention
The present invention relates to a multilayer substrate and a method of manufacturing the same.
2. Description of the Related Art
US 2006/0042078 A (corresponding to JP 2006-73763 A) discloses a manufacturing method of a multilayer substrate that includes an insulating base member and an electronic element embedded in the insulating base member. In the manufacturing method, the insulating base member includes a plurality of resin films and a part of the resin films has a through hole, in which the electric element is inserted. At least one of the resin films having the through hole is provided with a plurality of protruding members. The protruding members protrude from surrounding portions of the through hole into the through hole. The protruding members are arranged so that a distance between opposing tips (top ends) of the protruding members is shorter than an outside dimension of the electronic element. The electric element is inserted in the through hole while crushing the tips of the protruding members. A stacked body of the resin films, in which the electric element is arranged, is pressed with heat to form the multilayer substrate.
The electronic element inserted in the through hole is fixed by the resin film having the protruding members, thereby the electronic element is restricted from getting into an interlaminar of the stacked resin films or jumping out from the through hole due to vibrations generated by inserting another electronic element into an adjacent through hole or carrying the stacked body to a next process. Thus, the electronic element is restricted from displacing during a manufacturing process.
According experiments by the inventor of the present application, in a case where the electronic element is out of position with respect to the through hole when the electronic element is inserted in the through hole, the electronic element may chip off the protruding members and may generate a resin dust. In addition, the resin dust may affect a connection between an electrode in the electronic element and a conductive pattern. In contrast, in a case where the electronic element is positioned with respect to the through hole with a high accuracy, it may take a long time to inserting the electronic element. Thus, the positioning of the electric element with a high accuracy is unsuitable for a case where a plurality of electronic elements is inserted in a multilayer substrate.
It is required to restrict a generation of a resin dust when an electronic element is inserted in a through hole of stacked resin films, while inserting the electric element in a short time.